binary.rb

class Object
  def define_eigenmethod(m, &b)
    (class << self; self end).send(:define_method, m, &b)
  end
end

def Binary(ps)
  Class.new do
    define_eigenmethod(:unit) do |unit = nil, &b|
      unit || b ? @unit = unit || b : @unit || :to_i
    end

    define_method(:to_binary) do
      u = self.class.unit
      if u.is_a?(Array)
        u.map { |x| instance_variable_get("@#{x.to_s}").to_binary }.join
      else
        [u.is_a?(Proc) ? u.call : self.send(u)].pack(self.class.ps)
      end
    end

    define_eigenmethod(:new_from_binary) { |bin| new(*bin.unpack(self.ps)) }
    define_eigenmethod(:ps) { ps.is_a?(Array) ? ps.map(&:ps).join : ps }
  end
end